Why did Maharaj start demanding excessive Dakshina from Kashiram, leading to his financial ruin?

The entire episode was a spiritual lesson orchestrated by Maharaj to remove an obstacle from his devotee's path. Chapter 0 explains that as Kashiram continued to give, pride crept into his mind that he had the "power to give." To eliminate this pride, Maharaj began a barrage of demands for Dakshina. This forced Kashiram to exhaust his savings and even borrow from a grocer until he could no longer give. The purpose of this leela was to make Kashiram realize he did not have the power to give, and once this pride vanished, his financial condition began to improve once more.